With reference to FIG. 1, the mammary glands of a woman secrete milk and are accessory glands of the generative system. The glands are two hemispherical eminences lying within the superficial fascia and situated on the front and sides of the chest. Each gland extends from the second rib above to the sixth rib below, and from the side of the sternum to near the mid-axillary line. The weight and dimensions of the mammary glands differ at different periods of life and in different individuals. Before puberty the mammary glands are small in size, but enlarge as the generative organs become more completely developed. The glands increase during pregnancy and especially after delivery, and become atrophied in old age. The left gland is generally a little larger than the right. The deep or inner surface of each is nearly circular, flattened, or slightly concave, and has its long diameter directed upward and lateralward toward the axilla (which is the pyramidal space situated between the upper lateral part of the chest and the medial side of the arm). Each gland is separated from the fascia covering the Pectoralis major, Serratus anterior, and Obliquus externus abdominis by loose connective tissue. The subcutaneous surface of the mammary gland is convex and presents, just below the center, a small conical prominence, or papilla 10.
The mammary papilla or nipple 10 is a cylindrical or conical eminence situated about the level of the fourth intercostal space. It is capable of undergoing erection from mechanical stimulation, a change mainly due to the contraction of its muscular fibers. Its surface is wrinkled and provided with secondary papillae, and it is perforated by from 15 to 20 orifices, the apertures of lactiferous ducts 12. The base of the mammary papilla 10 is surrounded by an areola 14. Near the base of the papilla 10, and upon the surface of the areola 14, are numerous large sebaceous glands, the areolar glands, which become much enlarged during lactation, and present the appearance of small tubercles beneath the skin. The mammary papilla 10 consists of numerous vessels, intermixed with plain muscular fibers, which are principally arranged in a circular manner around the base.
The mammary gland consists of gland tissue; of fibrous tissue, connecting its lobes; and of fatty tissue in the intervals between the lobes. The subcutaneous surface of the mammary gland presents numerous irregular processes which project toward the skin and are joined to it by bands of connective tissue. It consists of numerous lobes, which are composed of lobules 16, connected together by areolar tissue, blood vessels, and ducts. The smallest lobules consist of a cluster of rounded alveoli, which open into the smallest branches of the lactiferous ducts 12. These ducts unite to form larger ducts, and these end in a single canal, corresponding with one of the chief subdivisions of the gland. The number of excretory ducts varies from 15 to 20, which are termed the tubuli lactiferi. They converge toward the areola 14, beneath which they form dilatations or ampullae 18, which serve as reservoirs for the milk, and, at the base of the papillae 10, become contracted and pursue a straight course to its summit, perforating it by separate orifices considerable narrower than the ducts themselves.
The fibrous tissue of the mammary glands invests the entire surface of the mamma. Bands of fibrous tissue traverse the gland and connect the overlying skin to the underlying pectoral fascia. These constitute the ligaments of Cooper. The fatty tissue 20 covers the surface of the gland, and occupies the interval between its lobes. It usually exists in considerable abundance, and determines the form and size of the gland. However, there is no fat immediately beneath the areola 14 and papilla 10.
Trauma is inflicted by conventional brassieres by constriction and pressure applied to the papillae and the lactiferous tubules, ampullae, and lobules. Aggravation to the breast is furthered by friction of conventional brassieres on the papillae and areolae during activities such as walking and exercising, and while lying on the breast while sleeping.
Conventional brassieres encase the entire breast and compress and constrain the papillae and areolar area where the lactiferous tubules are located. The compression of the papillae and the tubules are irritating factors that inflict trauma on the breasts and may contribute to the formation of cancer.
In view of the foregoing, there is a need in the art for a brassier which reduces trauma to the breasts, particularly trauma to the papillae and areolae.